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Trifecta 
20090309 

From Annie: I want to know how many combinations are there for the first 3 horses in
a race of 20 horses. For example, the horses can come in 1, 5, 7 or
7, 5, 1 which are totally different combos. I've only found formulas
where the 1, 2, 3 and 3, 2, 1 are counted as the same combo.
In horse racing every combo is different.
Thank you. Answered by Penny Nom. 


